Teledyne ULTRAFLOW 150, Руководство по эксплуатации, Страница: 28 / 162

ULTRAFLOW 150 GAS FLOW AND TEMPERATURE MONITOR
5.2.3.1 Configuration Devices
The Flow Mother Board FPGA is SRAM-based; therefore its internal memory is
volatile. Consequently, it must be configured each time power is cycled. This is
done automatically with an IC known as a Configuration Device. The
Configuration Device U5 is a flash memory that contains additional circuitry to
control the serial loading of configuration data into the FPGA. The configuration
data in U5 programs the gates and registers inside the FPGA to accomplish the
board’s design functions. It is important to realize this configuration is not the
same as the monitor’s calibration configuration, i.e. parameters such as Geometry
Properties, Calibration Properties, etc., which are usually entered by menu
selections via the Enhanced Remote Panel software.
The FPGA performs digital filtering on the incoming received signals. Since each
transducer type has a different center frequency, a different Configuration Device
is required to properly filter each one. There are three different types of
Configuration Devices, one for each type of transducer. See Table 5-1.
Table 5-1
Configuration Device U5 versus Transducer Type
TRANSDUCER TYPE
REQUIRED CONFIGURATION DEVICE U5
ES Labeled as X.50
LR003 Labeled as X.20
LR004 through LR007 Labeled as X.14
(where X is number that changes based on the firmware version of U5)
In the Enhanced Remote, the System Properties, Intrinsic Properties parameter
Transducer Type can be selected via menu control. This selection must match the
Configuration Device U5 or the monitor will not function. A Filter Mismatch
fault will be generated if the Transducer Type selection does not match
Configuration Device U5.
5.2.3.2 Transducer Drive Waveforms
The FPGA produces a digitized version of the ultrasonic tone burst wave packet
required to drive the transducers. The FPGA sends a digital representation of the
wave packet to the “B” half of a dual DAC where it is converted to an analog
signal and steered to the appropriate preamp by the transmit select signals of the
FPGA. Since this waveform is digitally created, it does not require tuning and is
virtually free of temperature drift. Figures 5-3A and 5-3B are examples of typical
waveforms for two different transducer types used in different applications.
Consult the Site Specification Data sheet of Appendix A for information on the
transducer configuration of your individual monitor
.
5-4